UPSC Prelims 2013–2026 — Science & Technology and Basic Science

Q1. “Membrane Bioreactors” are often discussed in the context of: (2024)

Q2. ‘Aerial metagenomics’ best refers to which one of the following situations? (2023)

Q3. ‘Microsatellite DNA’ is used in the case of which one of the following? (2023)

Q4. COVAXIN is an inactivated pathogen based vaccine. Which of the statements given above are correct?

Q5. Which one of the following statements best describes the role of B cells and T cells in the human body? (2022)

Q6. identify undesirable animal or plant materials in processed foods. Which of the statements given above is/are correct ?

Q7. Biofilms can exhibit antibiotic resistance. Which of the statements given above are correct ?

Q8. Bacteria and viruses are used as vectors. Which of the statements given above is/are correct?

Q9. A child inherits mitochondrial diseases entirely from mother and not from father. Which of the statements given above is/are correct?

Q10. Virus Which of the above can be cultured in artificial/synthetic medium?

Q11. In the context of recent advances in human reproductive technology, ‘Pronuclear Transfer” is used for (2020)

Q12. What is the Cas9 protein that is often mentioned in the news? (2019)

Q13. It can be used to produce crop plants that are resistant to virtual pathogens. Select the correct answer using the code given below:

Q14. With reference to the recent developments in science, which one of the following statements is not correct? (2019)

Q15. The term ‘ACE2’ is talked about in the context of (2021)

Q16. Common cold is sometimes caused by an adenovirus whereas AIDS is caused by a retrovirus. Which of the statements given above is/are correct?

Q17. Bollgard I and Bollgard II technologies are mentioned in the context of (2021)

Q18. These vaccines have no side effects and cause no allergic reactions. Select the correct answer using the code given below:

Q19. Human induced pluripotent stem cells can be injected into the embryo of a pig. Which of the statements given above is/are correct?

Q20. Gene silencing Which of the above is/are used to create transgenic crops?

Q21. Resist disease infestation Select the correct answer using the code given below:

Q22. from microorganisms to higher organisms Select the correct answer using the code given below:

Q23. What is the application of Somatic Cell Nuclear Transfer Technology? (2017)

Q24. It can be used to decipher the host-pathogen relationships in crops. Select the correct answer using the code given below:

Q25. In the context of the developments in Bioinformatics, the term ‘transcriptome’, sometimes seen in the news, refers to (2016)

Q26. With reference to Unmanned Aerial Vehicles (UAVs), consider the following statements: (2025) I. All types of UAVs can do vertical Landing. II. All types of UAVs can do automated hovering. III. All types of UAVs can use battery only as a source of power supply. How many of the statements given above are correct?

Q27. What is the common characteristic of the chemical substances generally known as CL-20, HMX and LLM-105, which are sometimes talked about in media (2025)

Q28. With reference to India’s defence, consider the following pairs: Aircraft type : Description I. Dornier 228 : Maritime patrol aircraft II. IL-7 : Supersonic combat aircraft III. C-17 Globe-master III : Military transport aircraft How many of the pairs given above are correctly matched?

Q29. The Indian Air Force was a part of this exercise. Select the answer using the code given below:

Q30. Tejas MK-1 How many of the above are considered fifth Generation fighter aircraft?

Q31. Agni-V is a medium-range supersonic cruise missile, while BrahMos is a solid-fuelled intercontinental ballistic missile. Which of the statements given above is/are correct?

Q32. Prithvi-II is a surface-to-surface missile and can be deployed to guard the metros against air attacks. Which of the statements given above is/are correct?

Q33. It can deliver one-tonne nuclear warheads about 7500 km away. Select the correct answer using the code given below:

Q34. Consider the following statements: (2025) Statement I: Activated carbon is a good and an attractive tool to remove pollutants from effluent streams and to remediate contaminants from various industries. Statement II: Activated carbon exhibits a large surface area and a strong potential for adsorbing heavy metals. Statement III: Activated carbon can be easily synthesized from environmental wastes with high carbon content. Which one of the following is correct in respect of the above statements?

Q35. GPS-Aided Geo Augmented Navigation (GAGAN) uses a system of ground stations to provide necessary augmentation. Which of the following statements is/are correct in respect of GAGAN? (2025) I. It is designed to provide additional accuracy and integrity. II. It will allow more uniform and high quality air traffic management. III. It will provide benefits only in aviation but not in other modes of transportation. Select the correct answer using the code given below.

Q36. Consider the following space missions: (2025) I. Axiom-4 II. SpaDeX III. Gaganyaan How many of the space missions given above encourage and support micro-gravity research?

Q37. Consider the following statements: (2024) Statement-I: Giant stars live much longer than dwarf stars. Statement-II: Compared to dwarf stars, giant stars have a greater rate of nuclear reactions. Which one of the following is correct in respect of the above statements?

Q38. Pulsars : Neutron stars that are formed when massive stars run out of fuel and collapse How many of the above pairs are correctly matched?

Q39. Which one of the following statements best reflects the idea behind the “Fractional Orbital Bombardment System” often talked about in the media? (2022)

Q40. The experiment will employ a trio of spacecraft flying in formation in the shape of an equilateral triangle that has sides one million kilometers long, with lasers shining between the craft.” The experiment in question refers to (2020)

Q41. Land surface temperature of a specific location. Select the correct answer using the code given below:

Q42. India will have its own satellite navigation system with full global coverage by the middle of 2021. Which of the statements given above is/are correct?

Q43. AstroSat is a 2000 kg satellite placed in an orbit at 1650 km above the surface of the Earth. Select the correct answer using the code given below.

Q44. made India the only country to be successful in making its spacecraft orbit the Mars in its very first attempt Which of the statements given above is/are correct?

Q45. Traffic studies Select the correct answer using the code given below:

Q46. The term ‘Goldilocks Zone’ is often seen in the news in the context of (2015)

Q47. Recently, scientists observed the merger of giant ‘blackholes’ billions of light-years away from the Earth. What is the significance of this observation? (2019)

Q48. Controlling the power grids Select the correct answer using the codes given below:

Q49. Matter warps its surrounding space-time. Which of the above is/are the predictions/predictions of Albert Einstein's General Theory of Relativity, often discussed in the media?

Q50. GSLV Mk III is a four-staged launch vehicle with the first and third stages l using solid rocket motors; and the second and fourth stages using liquid rocket engines. Which of the statements given above is/are correct?

Q51. It is buried deep in the ice. Which of the statements given above is/are correct?

Q52. Voyager 1 and 2 Exploring the outer solar system Select the correct answer using the code given below:

Q53. Consider the following statements: (2025) I. It is expected that Majorana 1 chip will enable quantum computing. II. Majorana 1 chip has been introduced by Amazon Web Services (AWS). III. Deep learning is a subset of machine learning. Which of the statements given above are correct?

Q54. Which one of the following words/phrases is most appropriately used to denote “an interoperable network of 3D Virtual worlds that can be accessed simultaneously by millions of users, who can exert property rights over virtual items”? (2024)

Q55. Tracking the migration of animals In how many of the above activities can the radars be used?

Q56. Which one of the following countries has its own Satellite Navigation System? (2023)

Q57. Wireless Local Area Network Which of the above are considered Short-Range devices/ technologies ?

Q58. Web 3.0 is operated by users collectively rather than a corporation. Which of the statements given above are correct?

Q59. Outlook, Hotmail and Yahoo! Mail are forms of SaaS. Which of the statements given above are correct?

Q60. Which one of the following is the context in which the term “qubit” is mentioned? (2022)

Q61. DIKSHA Which of the above are built on top of open-source digital platforms ?

Q62. In India, the term “Public Key Infrastructure” is used in the context of (2020)

Q63. VLC has no electromagnetic interference Communication Technology 4 293 Communication Technology

Q64. LTE is data-only technology and VoLTE is voice-only technology. Select the correct answer using the code given below:

Q65. When the alarm of your smartphone rings in the morning, you wake up and tap it to stop the alarm which causes your geyser to be switched on automatically. The smart mirror in your bathroom shows the day's weather and also indicates the level of water in your overhead tank. After you take some groceries from your refrigerator for making breakfast, it recognizes the shortage of stock in it and places an order for the supply of fresh grocery items. When you step out of your house and lock the door, all lights, fans, geysers and AC machines get switched off automatically. On your way to the office, your car warns you about traffic congestion ahead and suggests an alternative route, and if you are late for a meeting, it sends a- message to your office accordingly. (2018) In the context of emerging communication technologies, which one of the following terms best applies to the above scenario? (2018)

Q66. It is wireless technology and is several times faster than ‘WiFi’. Select the correct answer using the codes given below:

Q67. NFC can use encryption when sending sensitive information. Select the correct answer using the code given below:

Q68. Applications that depend on basic features of blockchain can be developed without anybody’s permission. Which of the statements given above is/are correct?

Q69. Assisting the hearing-impaired person. Select the correct answer using the code given below:

Q70. An electronic method of signing an electronic document and ensuring that the original content is unchanged. Which of the statements given above is/are correct?

Q71. Voice recognition Select the correct answer using the code given below:

Q72. Consider the following types of vehicles: (2025) I. Full battery electric vehicles II. Hydrogen fuel cell vehicles III. Fuel cell-electric hybrid vehicles How many of the above are considered as alternative powertrain vehicles?

Q73. Wood mill waste Which of the above can be used as feedstock for producing Sustainable Aviation Fuel?

Q74. RTGs can use Plutonium-238, which is a by-product of weapons development. Which of the statements given above are correct?

Q75. Which one of the following is the exhaust pipe emission from Fuel Cell Electric Vehicles, powered by hydrogen? (2024)

Q76. Recently, the term”pumped-storage hydropower” is actually and appropriately discussed in the context of which one of the following? (2024)

Q77. Rooftop solar photovoltaic units How many of the above are considered “Distributed Energy Resources”?

Q78. India is an important member of the ‘International Thermonuclear Experimental Reactor’. If this experiment succeeds, what is the immediate advantage for India? (2016)

Q79. Fuel cells produce electricity in the form of Alternating Current (AC). Which of the statements given above is/are correct?

Q80. India has a manufacturing base for Solar Thermal Technology but not for photovoltaics. Which of the statements given above is/are correct?

Q81. With reference to ‘Direct Air Capture’ an emerging technology, which of the following statements is/are correct? (2025) I. It can be used as a way of carbon sequestration. II. It can be a valuable approach for plastic production and in food processing. III. In aviation, it can be a source of carbon for combining with hydrogen to create low-carbon fuel. Select the correct answer using the code given below.

Q82. Consider the following statements: (2025) I. Indian Railways have prepared a National Rail Plan (NRP) to create a ‘future ready’ railway system by 2028. II. ‘Kavach’ is an Automatic Train Protection system developed in collaboration with Germany. III. ‘Kavach’ system consists of RFID tags fitted on track in station section. Which of the statements given above are not correct?

Q83. Nanoparticles of some commercial products which enter the environment are unsafe for humans. Which of the statements given above is/are correct ?

Q84. Bisphenol A (BPA), a cause of concern, is a structural/key component in the manufacture of which of the following kinds of plastics? (2021)

Q85. ‘Triclosan’, consider harmful when exposed to high levels for a long time, is most likely present in which of the following? (2021)

Q86. Solar power can be used for running centrifugal pumps and not the ones with piston. Which of the statements given above is/are correct?

Q87. Carbon nanotubes are biodegradable. Which of the statements given above are correct?

Q88. Collecting breath samples from spouting whales for DNA analysis At the present level of technology, which of the above activities can be successfully carried out by using drones?

Q89. Wireless transmission of electrical energy. Select the correct answer using the code given below:

Q90. Transparent displays are possible using OLEDs. Select the correct answer using the codes given below:

Q91. Nanotechnology can largely contribute to gene therapy. Select the correct answer using the code given below:

Q92. It will enable us to create better fuels for nuclear fission. Select the correct answer using the code given below:

Q93. Plant varieties are not eligible to be patented in India. Which of the statements given above is/are correct?

Q94. Data processing technologies Select the correct answer using the code given below:

Q95. CRISPR-Cas9 Particle Physics Which of the pairs given above is/are correctly matched?

Q96. Chinese fast food Monosodium glutamate Which of the pairs given above is/are correctly matched?

Q97. Which one of the following is a reason why astronomical distances are measured in light-years? (2021)

Q98. Weight of the lid Select the correct answer using the code given below.

Q99. The spectrum of visible light from sodium lamps is almost monochromatic while LED lamps offer significant colour advantages in street-lighting. Select the correct answer using the code given below.

Q100. Ball bearings are used in bicycles, cars, etc. because (2013)

Q101. Polestar being visible in the sky Which of the above are optical illusions?

Q102. Internal reflection Select the correct answer using the code given below:

Q103. The known forces of nature can be divided into four classes, viz., gravity, electromagnetism, weak nuclear force and strong nuclear force. With reference to them, which one of the following statements is not correct? (2013)

Q104. Artificial way of causing rainfall to reduce air pollution makes use of (2025)

Q105. Preparation of industrial lubricants Select the correct answer using the code given below:

Q106. Water can dissolve more substances than any other liquid because (2021)

Q107. Souring of milk Select the correct answer using the code given below:

Q108. In the context of electric vehicle batteries, consider the following elements: (2025) I. Cobalt II. Graphite III. Lithium IV. Nickel How many of the above usually make up battery cathodes?

Q109. Consider the following: (2025) I. Cigarette butts II. Eyeglass lenses III. Car tyres How many of them contain plastic?

Q110. Consider the following substances: (2025) I. Ethanol II. Nitroglycerine III. Urea Coal gasification technology can be used in the production of how many of them?

Q111. With reference to monoclonal antibodies, often mentioned in news, consider the following statements: (2025) I. They are man-made proteins. II. They stimulate immunological function due to their ability to bind to specific antigens. III. They are used in treating viral infections like that of Nipah virus. Which of the statements given above are correct?

Q112. Consider the following statements: (2025) I. No virus can survive in ocean waters. II. No virus can infect bacteria. III. No virus can change the cellular transcriptional activity in host cells. How many of the statements given above are correct?

Q113. Which one of the following is synthesised in the human body that dilates blood vessels and increases blood flow? (2024)

Q114. Probiotics help in the digestion of milk sugars. Which of the statements given above is/are correct?

Q115. Sugarcane can be cultivated using settlings prepared from tissue culture. Which of the statements given above is/are correct?

Q116. Mature plant cell has one large vacuole whilst an animal cell has many small vacuoles. Select the correct answer using the code given below:

Q117. Which of the following statements is not correct? (2019)

Q118. Multiple chronic diseases in some people. Select the correct answer using the code given below:

Q119. Wind blowing Which of the above spread plant diseases?

Q120. Lichens, which are capable of initiating ecological succession even on a bare rock, are actually a symbiotic association of (2014)

Q121. Fruits stored in a cold chamber exhibit longer storage life because (2013)

Q122. Many transplanted seedlings do not grow because (2013)

Q123. Viruses are transmitted from one organism to another by biological vectors only. Select the correct answer using the code given below:

Q124. HIV-AIDS Select the correct answer using the code given below:

Q125. Sodium Which of the minerals given above is/are required by the human body for the contraction of muscles?

Q126. plants Select the correct answer using the code given below.

Q127. Smallpox Which of the above diseases has/have been eradicated in India?

Q128. Alcoholic beverages can be produced by using maize. Which of the statements given above is/are correct?

Q129. Vegetative propagation can be practised most of the year. Select the correct answer using the code given below:

Q130. Vitamin E Night blindness Which of the pairs given above is/are correctly matched?

Q131. Which of the following statements about DHRUV64 is/are correct? 1. It is the third chip fabricated under the DIR-V Programme with an overall aim to enable the creation of microprocessors for India. 2. It is India's first homegrown 1.0 GHz, 64- bit dual-core microprocessor. Select the answer using the code given below: (2026)

Q132. The Bureau of Indian Standard (BIS) recently introduced a national standard to test and assess bomb disposal system. Which of the following statements with regard to this system is/are correct? 1. The new standard is known as IS 19445: 2025. 2. It will improve interoperability of equipment across agencies. 3. It was developed by TBRL, DRDO in collaboration with the 30th Central Scientific Research Institute, Russia. Select the answer using the code given below: (2026)

Q133. X', born in the UK, was conferred the Nobel Prize in 2025. He was a professor in an American university when this prize was announced. Identify 'X': (2026)

Q134. Which one of the following pairs of semiconductor plants in India and their locations is NOT correctly matched? (2026)

Q135. Which of the following statements regarding the features of blockchain technology are correct? 1. Records stored in the database may be made visible to relevant stakeholders without risk of alteration. 2. Copies of the entire database are stored on multiple computers on a network, syncing within seconds. 3. Consortium blockchain is a blend of public and private blockchains allowing selective data access. 4. Mathematical algorithms make it impossible to change or delete any data once recorded and accepted. Select the answer using the code given below: (2026)

Q136. Which of the following statements with regard to genetic medicine is/are correct? 1. Genetic medicines correct/compensate for the faulty genes responsible for disease. 2. Engineered viruses and lipid nanoparticles are used as carriers of the genetic medicine. 3. Genetic medicines alter the entire DNA sequence. Select the answer using the code given below: (2026)

Q137. Which of the following statements with regard to Large Language Models (LLMs) used in machine learning is/are correct? 1. LLMs assign probabilities to the next possible words and then pick the one with the highest probability. 2. LLMs process data through mathematical optimization to minimise prediction errors. 3. LLMs produce unbiased outputs. Select the answer using the code given below: (2026)

Q138. Which of the following statements with regard to stealth technology is/are correct? 1. Stealth objects have a very small radar cross- section and are coated with Radar Absorbing Material. 2. Stealth objects can be detected using specific frequencies. 3. Stealth objects are coated with metamaterials to increase the scattering of electromagnetic radiation. Select the answer using the code given below: (2026)

Q139. Which of the following statements with regard to Black Boxes used in modern aircrafts is/are correct? 1. They carry a beacon emitting red light pulses to facilitate underwater detection. 2. They record both the cockpit voice and flight data. 3. Their memory units are made using either stainless steel or titanium. Select the answer using the code given below. (2026)

Q140. Consider the following statements with regard to involvement of private entities in India's space programme: 1. The Indian National Space Promotion and Authorisation Centre (IN-SPACe) is an autonomous agency formed to facilitate participation of private entities. 2. Agnikul Cosmos launched the world's first flight using 3D- printed rocket engine. 3. Skyroot Aerospace has developed liquid fuel for GSLV. Which of the statements given above is/are correct? (2026)

Q141. Which of the following statements with regard to drone swarms is/are correct? 1. They use Terahertz band of frequency to communicate with the command centre. 2. Individual drones in the swarm can communicate with other drones in the swarm. 3. GPS Spoofing is a commonly used technique to counter drone swarm attack. Select the answer using the code given below: (2026)

Q142. Which of the following statements with regard to GenomeIndia Project is/are correct? 1. It is a part of the Human Genome Project. 2. The project is funded by the Department of Biotechnology (DBT), Government of India. 3. Its primary aim is to build a catalogue of genetic diversity of the Indian population. Select the answer using the code given below: (2026)

Q143. Which of the following statements with regard to the National Quantum Mission (NQM) is/are correct? 1. It aims at developing intermediate-scale quantum computers with 50–1000 physical qubits. 2. Its implementation includes setting up of four Thematic Hubs (T- Hubs) in academic and national R&D institutes across India. Select the answer using the code given below: (2026)

Q144. Which of the following statements with regard to India's Deep Ocean Mission is/are correct? 1. It was launched by the Ministry of Ports, Shipping and Waterways, Government of India. 2. Matsya-6000 has been designed to carry 3 people for deep sea exploration. 3. Samudrayaan is a project under this mission. Select the answer using the code given below: (2026)

Q145. Consider the following statements about Mission Sudarshan Chakra of India: 1. It aims to enhance India's air defence, ballistic missile defence and aerial offensive capabilities. 2. This Mission is being designed to enhance rapid, precise, and powerful defence responses, reinforcing India's strategic autonomy. 3. One of the aims of this Mission is to cover all public places of India by an expanded nationwide security shield by 2035. Which of the statements given above is/are correct? (2026)

Q146. Consider the following statements with respect to the AI Impact Summit, 2026 held in New Delhi: 1. The Summit's intellectual framework was based on three foundational Sutras: People, Planning, and Progress. 2. The Preamble of the Summit stresses Democratising AI Resources, which acknowledges the Charter for Democratic Diffusion of AI as a binding framework to support locally relevant innovation and strengthen resilient AI ecosystems while respecting national laws. 3. The New Delhi Declaration on AI Impact was structured around seven Access Chakras (Pillars), which included Access for Social Empowerment, AI for Science, and Secure and Trusted AI. Which of the statements given above is/are correct? (2026)

Q147. Which of the following items of defence hardware is/are manufactured in India? 1. Su-30 MKI Fighter Jets 2. T-90 MK-III Tanks 3. Akula Class Submarine Select the answer using the code given below: (2026)